Castro wants to renew the federal "assault weapons" ban from 1994 that expired in 2004.
He has also pushed for universal background checks on secondhand transfers, commonly known as the "gun show loophole."
While HUD secretary, Castro issued guidance to boost fair housing rights, which applied to individuals with arrest records and freed prison inmates.
Castro's campaign unveiled a policing plan that would restrict use of force for police officers, increase use of body cameras, and combat the school-to-prison pipeline through disciplinary reforms in schools, including unconscious bias training.
The plan would also require police to obtain written consent for vehicle searches and ban stop and frisk policies.
Police would be required to undergo pre-employment screening to identify potential prejudices.
Castro's plan would implement a national database of decertified police officers and create "civilian oversight boards" in cities and communities.
At July's Democratic primary debate, Castro criticized former Vice President Joe Biden for his authorship of the 1994 crime bill and called for a national standard on the use of force.