For decades, venture capital and private equity firms have tapped public employee unions as a major source of funding for their investments in startups. Among those investors are the pension funds affiliated with police unions.

Dozens of venture firms, including NEA, Spark Capital and IVP, count police pension funds as limited partners, according to The Information’s analysis of financial reports published by these funds. That’s in addition to the hundreds of PE funds, including huge firms like Apollo and KKR, that have taken money from police unions. These investments illustrate the financial ties that link Silicon Valley and police workers at a time when civil rights advocates and some state lawmakers are pushing for police reform. The connections raise the possibility that venture firms could come under pressure to distance themselves from these limited partners.