I was able to drop the existing index (note that the name as displayed in the exception was not the name as displayed in cqlsh) and then create the solr index. However this seems like a bug.
Creating index...
<?xml version="1.0" encoding="UTF-8"?>
<response>
<lst name="responseHeader"><int name="status">500</int><int name="QTime">480</int></lst><lst name="error"><str name="msg">Unable to create core: dev.person</str><str name="trace">org.apache.solr.common.SolrException: Unable to create core: dev.person
at org.apache.solr.core.CoreContainer.recordAndThrow(CoreContainer.java:1461)
at org.apache.solr.core.CassandraCoreContainer.create(CassandraCoreContainer.java:300)
at com.datastax.bdp.cassandra.index.solr.SolrCoreResourceManager.createCore(SolrCoreResourceManager.java:271)
at com.datastax.bdp.cassandra.index.solr.CassandraCoreAdminHandler.handleCreateAction(CassandraCoreAdminHandler.java:121)
at org.apache.solr.handler.admin.CoreAdminHandler.handleRequestBody(CoreAdminHandler.java:144)
at org.apache.solr.handler.RequestHandlerBase.handleRequest(RequestHandlerBase.java:135)
at org.apache.solr.servlet.SolrDispatchFilter.handleAdminRequest(SolrDispatchFilter.java:615)
at org.apache.solr.servlet.SolrDispatchFilter.doFilter(SolrDispatchFilter.java:206)
at org.apache.solr.servlet.SolrDispatchFilter.doFilter(SolrDispatchFilter.java:155)
at com.datastax.bdp.cassandra.index.solr.CassandraDispatchFilter.doFilter(CassandraDispatchFilter.java:92)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.datastax.bdp.cassandra.audit.SolrHttpAuditLogFilter.doFilter(SolrHttpAuditLogFilter.java:194)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.datastax.bdp.cassandra.index.solr.auth.CassandraAuthorizationFilter.doFilter(CassandraAuthorizationFilter.java:95)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.datastax.bdp.cassandra.index.solr.auth.DseAuthenticationFilter.doFilter(DseAuthenticationFilter.java:102)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Thread.java:662)
Caused by: javax.xml.parsers.ParserConfigurationException: The following index is not a Solr one: dev_person_state_index
at org.apache.solr.core.CassandraCoreContainer.addColumnMetaData(CassandraCoreContainer.java:872)
at org.apache.solr.core.CassandraCoreContainer.createOrModifyCassandraSchema(CassandraCoreContainer.java:676)
at org.apache.solr.core.CassandraCoreContainer.create(CassandraCoreContainer.java:279)
... 29 more
</str><int name="code">500</int></lst>
</response>