By Rachel Lern­er1

The Fourth Amend­ment right to be free from war­rant­less search­es and seizures in one’s home is a deeply engrained con­sti­tu­tion­al pro­tec­tion.2 How­ev­er, as the bound­aries of what con­sti­tutes a “home” have become increas­ing­ly unclear in our urban­ized world, the ques­tion has become: where do our con­sti­tu­tion­al bound­aries start and where do they end? Does the Fourth Amendment’s pro­tec­tion extend to a shared apart­ment? A shared base­ment lounge? A shared hall­way clos­et? How do we bal­ance our core Fourth Amend­ment right to be pro­tect­ed in spaces “inti­mate­ly linked” to our homes3 with the need to pro­tect the pub­lic safe­ty of an urban­ized pop­u­la­tion who fre­quent­ly use shared spaces?

This piece will argue that a locked stor­age unit shared between two cotenants in an apart­ment build­ing deserves to have con­sti­tu­tion­al pro­tec­tion, under both a Dunn cur­tilage stan­dard4 and a Katz rea­son­able expec­ta­tion of pri­va­cy stan­dard.5 Addi­tion­al­ly, if the shared space is clear­ly demar­cat­ed between the two cotenants, law enforce­ment, even if grant­ed entry into the stor­age unit by one con­sent­ing cotenant, must still seek a judi­cial­ly approved war­rant if they wish to search the entire stor­age unit. Oth­er­wise, the search would be con­sti­tu­tion­al­ly invalid.

* * * * *

Deter­min­ing whether a search occurred under Fourth Amend­ment jurispru­dence often pro­ceeds along one of two main lines of rea­son­ing. The first is based in prop­er­ty rights, espe­cial­ly in the home. The sec­ond inquires as to rea­son­able expec­ta­tions of privacy.

First, the Supreme Court has said that the core of the Fourth Amend­ment is “the right of a man to retreat into his own home and there be free from unrea­son­able gov­ern­men­tal intru­sion.”6 Con­sti­tu­tion­al jurispru­dence defines the area “imme­di­ate­ly sur­round­ing and asso­ci­at­ed with the home” as “part of [the] home itself for Fourth Amend­ment pur­pos­es.”7 This area, defined as “cur­tilage,” is “inti­mate­ly linked to the home, both phys­i­cal­ly and psy­cho­log­i­cal­ly” and is, accord­ing­ly, where “pri­va­cy expec­ta­tions are most height­ened.”8

Whether an area is cur­tilage is heav­i­ly depen­dent upon the facts of the case. Specif­i­cal­ly, Unit­ed States v. Dunn estab­lished that courts should con­sid­er four fac­tors: (1) “the prox­im­i­ty of the area claimed to be cur­tilage to the home,” (2) “whether the area is includ­ed with­in an enclo­sure sur­round­ing the home,” (3) “the nature of the uses to which the area is put,” and (4) “the steps tak­en by the res­i­dent to pro­tect the area from obser­va­tion by peo­ple pass­ing by.”9 As is often the case in mak­ing fac­tu­al deter­mi­na­tions, the Dunn court rec­og­nized that these fac­tors must not be “mechan­i­cal­ly applied,” but are “use­ful ana­lyt­ic tools” to test “whether the area in ques­tion is so inti­mate­ly tied to the home itself that it should be placed under the home’s ‘umbrel­la’ of Fourth Amend­ment pro­tec­tion.”10

Even if an area is not cur­tilage with­in the mean­ing of Dunn, one may still have a rea­son­able expec­ta­tion of pri­va­cy with­in the unit, despite its lack of con­nec­tion to the home. The Supreme Court has held that “the Fourth Amend­ment pro­tects peo­ple, not places” and has dis­avowed the premise that phys­i­cal prop­er­ty bound­aries con­trol the right of the gov­ern­ment to engage in a war­rant­less search­es and seizures.11 Instead, the Court has built upon the tra­di­tion­al prop­er­ty-based cur­tilage under­stand­ing of the Fourth Amend­ment to extend con­sti­tu­tion­al pro­tec­tion to areas in which the defen­dant har­bors a “rea­son­able expec­ta­tion of pri­va­cy.”12 The “rea­son­able expec­ta­tion” test, adopt­ed by the Supreme Court in Katz, dic­tates that a court should deter­mine, first, whether the defen­dant exhib­it­ed an actu­al expec­ta­tion of pri­va­cy, and sec­ond, whether his expec­ta­tion is one that soci­ety is pre­pared to rec­og­nize as rea­son­able.13

In ana­lyz­ing whether one’s expec­ta­tion of pri­va­cy is “rea­son­able,” the Supreme Court has con­sid­ered a vari­ety of fac­tors, includ­ing “whether the par­ty can exclude oth­ers from that place; whether the par­ty took pre­cau­tions to main­tain the pri­va­cy; and whether the par­ty had a key to the premis­es.”14 A cotenant who has tak­en sub­stan­tial and exten­sive steps to exclude the pub­lic from her locked space and main­tain her pri­va­cy can sat­is­fy both the sub­jec­tive and objec­tive ele­ments of the analy­sis under Katz.15 Sim­ply by tak­ing those steps, she man­i­fests a sub­jec­tive expec­ta­tion of pri­va­cy, and an urban, space-con­strained soci­ety should rec­og­nize that expec­ta­tion as reasonable.

* * * * *

A locked stor­age unit, though com­mon­ly shared in an urban set­ting, is a con­sti­tu­tion­al­ly pro­tect­ed area under the Fourth Amendment.

Fol­low­ing the prop­er­ty ratio­nale of Dunn, the stor­age unit falls with­in the purview of “cur­tilage.” The only rea­son­able con­clu­sion upon appli­ca­tion of the four fac­tors estab­lished by Dunn is that the Fourth Amend­ment pro­tects a locked, shared stor­age unit. A locked, shared stor­age unit is typ­i­cal­ly prox­i­mate­ly adja­cent to one’s apart­ment, used as one would use a home, and is iso­lat­ed from pub­lic view. As the Court not­ed in Jar­dines, “one virtue of the Fourth Amendment’s prop­er­ty-rights base­line is that it keeps easy cas­es easy.”16 That ratio­nale should apply to a shared stor­age unit in an apart­ment building.

Fol­low­ing a pri­va­cy ratio­nale under Katz, one who has exhib­it­ed an actu­al expec­ta­tion of privacy­—such as by lock­ing a stor­age unit and exclud­ing anoth­er cotenant from access­ing her belongings—and whose expec­ta­tion soci­ety rec­og­nizes as rea­son­able may rely on the Fourth Amend­ment as pro­tec­tion against war­rant­less search­es of a shared stor­age unit, even if that unit is out­side the phys­i­cal bound­aries of one’s home. An urban, space-con­strained soci­ety should rec­og­nize that expect­ing pri­va­cy in a locked and labeled stor­age unit is rea­son­able.17 Thus under Katz, law enforce­ment offi­cers con­duct a search sub­ject to the Fourth Amend­ment when­ev­er they enter such a space.

Fur­ther­more, under either the “cur­tilage” stan­dard or “rea­son­able expec­ta­tion” test, the fact that one cotenant vol­un­tar­i­ly opens the door to a shared stor­age unit at an offi­cers’ request does not nec­es­sar­i­ly dimin­ish anoth­er cotenant’s Fourth Amend­ment pro­tec­tion in that area.

Law enforce­ment may rely on an individual’s con­sent to a search only if that indi­vid­ual is autho­rized to give con­sent and con­sents vol­un­tar­i­ly.18 In shared spaces, con­sent by third par­ties is valid only when the police can rea­son­ably believe the con­sent­ing par­ty pos­sess­es com­mon author­i­ty over the entire­ty of the shared space.19 The touch­stone of this rea­son­able­ness inquiry requires look­ing at the par­tic­u­lar facts con­cern­ing a spe­cif­ic shared space and assess­ing the “social expec­ta­tions” the par­ties of the shared space may hold.20 If there is no rea­son­able belief in com­mon author­i­ty over a shared stor­age unit, there is no valid con­sent to a search of the entire stor­age unit.21

There­fore, one cotenant does not always have author­i­ty to con­sent to a search of the oth­er cotenant’s items.22 For exam­ple, if a “Neigh­bor Agree­ment” is post­ed on the door of the stor­age unit, which makes it clear that one cotenant is for­bid­den to touch or move any of the oth­er cotenant’s belong­ings, it would be unrea­son­able for offi­cers to con­clude that one cotenant could con­sent to a search of the other’s belong­ings. Addi­tion­al­ly, if areas are clear­ly demar­cat­ed, con­sent to one area does not rea­son­ably extend to con­sent for all areas. 23

Addi­tion­al­ly, Jus­tice Scalia’s rea­son­ing regard­ing Fourth Amend­ment pro­tec­tions in Flori­da v. Jar­dines also illus­trates the lim­its to a cotenant’s con­sent. Even though a cotenant might vol­un­tar­i­ly open the door to the locked stor­age unit for offi­cers, “[t]he scope of a license – express or implied – is lim­it­ed not only to a par­tic­u­lar area but also to a spe­cif­ic pur­pose.”24 Back­ground social norms and the unique cir­cum­stances of the con­sent will affect this analy­sis. For exam­ple, while find­ing “a vis­i­tor knock­ing on the door is rou­tine” for some, spot­ting “th[at] same vis­i­tor explor­ing the front path with a met­al detec­tor . . . would inspire most of us to – well, call the police.”25 There­fore, if the offi­cers approached a cotenant, sought con­sent to enter a stor­age unit, and announced their pur­pose was to speak to her about the oth­er cotenant, with­out explic­it­ly or implic­it­ly telling her that they intend­ed to search the oth­er cotenant’s items, the con­sent to enter the unit does not rea­son­ably extend to search­ing the entire unit beyond the con­sent­ing cotenant’s items.

* * * * *

In sum, a shared, locked stor­age unit enjoys con­sti­tu­tion­al pro­tec­tion under the Fourth Amend­ment, both under the Dunn cur­tilage stan­dard and the Katz “rea­son­able expec­ta­tions” test. Addi­tion­al­ly, one cotenant can­not always give rea­son­able con­sent to a search of the entire unit, espe­cial­ly when areas are clear­ly demar­cat­ed or detailed through a post­ed “Cotenant Agree­ment.” There­fore, search­ing such a space requires prob­a­ble cause and a warrant.


1. Rachel Lern­er is a 3L at New York Uni­ver­si­ty School of Law. This piece is a com­men­tary on the 2017 Evan A. Evans Con­sti­tu­tion­al Law Moot Court Com­pe­ti­tion host­ed by the Uni­ver­si­ty of Wis­con­sin Moot Court Board. The views expressed in this arti­cle do not nec­es­sar­i­ly rep­re­sent the views of the author on this point of law. Rather, this arti­cle is a dis­til­la­tion of one side of an argu­ment assigned to the author at the 2017 Evan A. Evans Con­sti­tu­tion­al Law Moot Court Com­pe­ti­tion. For anoth­er com­men­tary from this com­pe­ti­tion, see  Search, Seizure, and the Smart­phone: Rethink­ing Pri­va­cy Pro­tec­tions in the Dig­i­tal Age.
2. See Pay­ton v. New York, 445 U.S. 573, 586 (1980) (“It is a ‘basic prin­ci­ple of Fourth Amend­ment law’ that search­es and seizures inside a home with­out a war­rant are pre­sump­tive­ly unrea­son­able.” (foot­note omitted)).
3. See Flori­da v. Jar­dines, 569 U.S. 1, 6–7 (“the area ‘imme­di­ate­ly sur­round­ing and asso­ci­at­ed with the home’ . . . is ‘inti­mate­ly linked to the home’” and thus war­rants Fourth Amend­ment protection).
4. See Unit­ed States v. Dunn, 480 U.S. 294, 301 (1987) (estab­lish­ing that whether an area is con­sti­tu­tion­al­ly pro­tect­ed cur­tilage is heav­i­ly depen­dent on the facts).
5. See Katz v. Unit­ed States, 389 U.S. 347, 351 (1967) (hold­ing that con­sti­tu­tion­al pro­tec­tion extends to areas out­side the home in which peo­ple har­bor rea­son­able expec­ta­tions of privacy).
6. Sil­ver­man v. Unit­ed States, 365 U.S. 505, 511 (1961).
7. Oliv­er v. Unit­ed States, 466 U.S. 170, 180 (1984).
8. Cal­i­for­nia v. Cirao­lo, 476 U.S. 207, 213 (1986).
9. Unit­ed States v. Dunn, 480 U.S. 294, 301 (1987); see also L.A. Police Pro­tec­tive League v. Gates, 907 F.2d 879, 885 (9th Cir. 1990) (rely­ing on the Dunn test to find an area was con­sti­tu­tion­al­ly pro­tect­ed cur­tilage); Unit­ed States v. Moor­ing, 137 F.3d 595, 596–97 (8th Cir. 1998) (same).
10. Dunn, 480 U.S. at 301.
11. Katz v. Unit­ed States, 389 U.S. 347, 351 (1967).
12. Flori­da v. Jar­dines, 133 S. Ct. 1409, 1417 (2013) (hold­ing that Fourth Amend­ment pro­tec­tions extends out­side the bound­aries of one’s home and prop­er­ty); see also Unit­ed States v. Hoff­man, 677 F. Supp. 589, 596 (E.D. Wis. 1998) (“[A] per­son can have a pro­tect­ed expec­ta­tion of pri­va­cy in build­ings . . . that are locat­ed far out­side the area of the cur­tilage of the home.”).
13. See Smith v. Mary­land, 442 U.S. 735, 740 (1979) (cit­ing Katz, 389 U.S. at 351, 361).
14. Unit­ed States v. McCast­er, 193 F.3d 930, 933 (cit­ing Rawl­ings v. Ken­tucky, 448 U.S. 98, 105 (1980)).
15. See Unit­ed States v. San­ta Maria, 15 F.3d 879, 883 (9th Cir. 1994) (find­ing that the defen­dant had a rea­son­able expec­ta­tion of pri­va­cy in a locked unit in which he kept his tools).
16. Jar­dines, 133 S. Ct. at 1417.
17. See McCast­er, 193 F.3d at 933; San­ta Maria, 15 F.3d at 883 (find­ing that locked and pri­vate spaces are pro­tect­ed under the Katz rea­son­able­ness test).
18. See Unit­ed States v. Mat­lock, 415 U.S. 164, 171 (1974).
19. See Illi­nois v. Rodriguez, 497 U.S. 177, 179 (1990) (hold­ing that a search of an entire shared apart­ment was con­sti­tu­tion­al after the con­sent­ing renter referred to it as “our” apart­ment, and said that she had clothes and fur­ni­ture inside).
20. See Geor­gia v. Ran­dolph, 547 U.S. 103, 111 (2006) (“The con­stant ele­ment in assess­ing Fourth Amend­ment rea­son­able­ness in con­sent cas­es … is the great sig­nif­i­cance giv­en to wide­ly shared social expec­ta­tions, which are nat­u­ral­ly enough influ­enced by the law of prop­er­ty, but are not con­trolled by its rules).
21. See Mat­lock, 415 U.S. at 170.
22. See Unit­ed States v. Amratiel, 622 F.3d 914, 915 (8th Cir. 2010) (hold­ing that con­sent by a third par­ty is valid only if an offi­cer can “rea­son­ably rel[y] on a third party’s demon­stra­tion of appar­ent author­i­ty” over the prop­er­ty being searched).
23. Cf. Unit­ed States v. Penaloza-Romero, No. CRIM. 13–36 RHK/TNL, 2013 WL 5472283, at *7 (D. Minn. Sept. 30, 2013) (hold­ing that offi­cers had a right to search a com­mon hall­way of a build­ing under the express­ly grant­ed author­i­ty of the com­plex manager).
24. Jar­dines, 133 S. Ct. at 1416.
25. Id.